A brief guide to the Catholic Church's sainthood procedure

VATICAN CITY (Reuters) - Pope Francis on Sunday formally recognizes the sainthood of two of his predecessors, John XXIII, who reigned from 1958 to 1963, and John Paul II, who was pontiff from 1978 to 2005.

Here is a brief summary of how the Roman Catholic Church recognizes sainthood.

The process that can lead to sainthood, known as a "cause", cannot usually start until five years after a person's death.

In some cases, this five-year waiting period can be waived by a pope if there is overwhelming evidence that the person under consideration lived a holy life.

Pope John Paul waived the five-year period for Mother Teresa of Calcutta, who died in 1997, and Pope Benedict waived it for the sainthood cause of Pope John Paul, who died in 2005.

In the early years of the Church, a saint could be declared such by acclamation by the people or by cardinals or by papal decree.

Today, the Vatican department that studies sainthood causes is known as the Congregation for the Causes of Saints. Its origins date back to 1588 but the department has been modified several times over the years.

After the Congregation accepts the name of a person to be considered for sainthood, that person is given the title "Servant of God".

If initial investigations show that the candidate for sainthood lived what is known as a life of "heroic virtues" that person is given the title "Venerable".
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